Centrifugal pump.



F. W. KROGH.

GBNTRIFUGAL PUMP. l

10N FILED JUNI: 29

Patented N0v.29, 1910.

2 SHBETS-SHEET 1.

and

P. W. KROGH. GBNTRIPUGAL PUM.

APPLIOATION FILED JUNE 29, 1909. 977, 1 01 l Patented Nov. 29, 1910.

FERDINAND W. KROGH, OF SAN FRANCISCO, CALIFORNIA.

CENTRIFUGAL PUMP.

Specication of Letters Patent. Patented NOV. 29', 1910.

Application filed .Tune 29, 1909. Serial No. 505,079.

To all whom 'it may concern:

Be it known that I, FERDINAND W. KRoGH,

citizen of the United States, residing in the city and county of SanFrancisco and State of California, have invented new and usefulImprovements in Centrifugal Pumps,- of which the following is aspecification.

My invention relates to improvements in what are known as centrifugalimpeller pumps.

It consists in a means for more perfectly balancing the running parts ofthe pump with relation to the suction and discharge pressure, and inautomatically regulating these pressures.

It also comprises details of construction and combinations of parts ashereinafter more fully described and claimed, having reference to theaccompanying drawings, in which- Figure 'l is a sectional view of theimpeller. F ig. 2 is a section of the pump taken in the plane of itsaxis. "Fig 3 is a view showingr a plurality o`f pumps connected inseries. Fig. 4 shows the application to a double suction.

In this class of pumps there is a wide vari'- ation between the pressureon the inlet or suction side of the impeller and the discharge side,which is at all times under a considerable pressure. c

It is the object of my invention to provide a means for automaticallyequalizing such pressures at all times, so that the moving parts will beperfectly balanced within their casing.

A is a casing which may be in one or more parts, each containing arevoluble impeller 2 mounted upon a shaft 3 through which power isapplied in any suitable manner to revolve the impeller.

The impeller may be in the form -of a disk having the curved water-ways4, and these water-ways connect through the hubvor central portion, asat 5, with the inlet or suc tion pipe or passage 6. By the rapidrevolution of this impeller when charged with the liquid, a centrifugalaction is set up which draws the water into the impeller, and throws itoutwardly into the annular surrounding passage 7, which passage connectswith thejdischarge pipe 8, this pipe being substantially tangent withthe annular passage 7 so that the liquid Will'be delivered therefrom.

O u I n In case the pumps are arranged in series,

as shown in Fig. 3, the discharge from thev rst impeller will bereturned through passages as at 9, into the hub of the second impeller,thence passing youtwardly through the curved waterways 4a, and so onthrough as many series as it may be found desirable to employ.

It will be manifest that the pressures involved by thel suction anddischarge acting in the line of the shaft, will tend to force theimpeller constantly to one side within the shell or casing A. In orderto overcome this difiiculty, I have shown the' following constructionThe hub 10 of the impeller has flanges 11 projecting on each side, andadapted to contact with the opposite sides of the that as the impellerrevolves, the ends of the hub revolve within these flanges, and thusform the chambers 12-12a as shown. A In order to form more perfectjoints between the annular flanges 13 and the hub, I have shown rings 15fitting around the ends of the hub, and these rings are constantlypressed againstthe inner ends of the flanges 13 by springs 16.

14 are independent passages made in the runner, and these passagesextend from the periphery of the runner, and open through the end of thehub opposite to the suction, and radially opposite to the openings ofthe impeller passa es 4 which communicate ywith the -suction en Therevolution of the impeller causes a constant centrifugal action which,drawing .Water through the suction pipe will discharge it through thepassages 4 and into the annular chambers 7 whence it passes to thed'scharge, ory tothe following casingv as the case may be. The pressure'Within this annular discharge passage `is very considerable, and thispressure is allowed to pass intolthe sides of the casing A by reason ofthe. space within the casing around the impeller, and as the lit betweenthe part 1.0 and the anges the runner thatsaid runner 13 of the casingis a running fit, a certain amount of water will leak into the chambers12-121. The action of the suction through the waterways 4, and theentrance thereto at 5, constantly acts to draw the water out of thechamber `12,'and thus the tendency of v the pressure of the wateradmitted into the chamber 12 would be to force t-he impeller toward thesuction side of the casing; but the supplemental passages 14 openinginto the interior'end of the hub, and opposite to the suction side, theleakage from the chamber 12'r1 through the space between the casing andthe flange 11 at that end of the hub, will be drawn out by thecentrifugal action of the water through the passages 14. Thus, if thereis a greater suction of Water through the passages 14 than through thepassages 4, the tendency of the hub andthe impeller will be tomove'toward the side of the casing opposite to the suction, and if theincrease is from the suction side, the impeller will be moved in thatdirection. In other words, the centrifugal Vaction of the pump producesthe suction through the inner pipe, 6, and this suction tends' toproduce a vacuum which causes such pressure upon will be forced towardthe suction side. This action takes place up to a certain neutral pointwithin the pump; beyond that the centrifugal force commences to raisethe water through the discharge pipe and that will produce 'a directpressure in the opposite direction, the pressure being reversed andbecoming an actual back pressure. This neutral point is ditl'icult tolocate even by the use of the gages, but it is at this point that theanges, 11 and 13, co-act to 'continually adjust the balancing of therunner. When the runner moves toward the suction side it opens a spacebetween the flange, 11, and the inner side of the case and water may nowpass from the discharge which is nthe pressure side of the pump into thechannel, 12, and thus create a counter-pressure against the suction.When the runner moves\ toward the opposite side of the case it enablesthis water to pass from the channel, 12, into the suction passage, thustending to create a vacuum within the channel, 12, and this actingagainst the end of the hub presented to the channel serves to againequalize the pressure in that direction. By reason of the 'foregoingconstruction an automat-ic bala\ce of the impeller within its casing isnstantly maintained. It will be seen by reference to Fig. 3 that thesame operation is repeated in each of the subsequent impelletls, and`thus the apparatus will be made self-balancing, and any tendency of theimpeller to run toward either side within the casing will be constantlyneutralized. y

In Fig. 4 ysuction pipes or passages 6 are connected with opposite sidesof the casing.

Under this condition it will be seen that the variation in pressures,upon opposite sides of the impeller will still be 1)alanced asheretofore described, by the action within the chambers 12, and 12a.

Having thus described my invention, what I claim and desire to secure byLetters Patent is` 1. The combination in a centrifugal pump, of a casinghaving central inlet and peripheral discharge passages, an impellerrevoluble within the casing, the impeller having curved water waysconnecting with the inlet passage and having a hub through the center ofone side of which the inlet ends of the Water-ways open, said hub andthe innerl faces of the casing having annular flanges forming with theadjacent sides of the casing and hub, intermediate chambers, and saidimpeller having other passage-ways which are independent of thefirst-named ones and whose inner ends open through the side of the hubopposite to that through which the inlet ends of the first passagesopen, both of said passages leading outwardly through the periphery ofthe impeller.

2. The combination in a centrifugal pump of a casing and co-actingimpeller, said impeller having a hub and said hub having annular flangeson its opposite faces between its periphery and axial center, and saidcasing having inwardly extending flanges within which the periphery ofthe hub has a running fit, said impeller having two sets of water-ways,one of which opens through one .side of the hub and leads outwardlythrough the periphery of the impeller,'andl the other has its inlet endopening through the side of the hub opposite to that containing theinlet end of the rstnamed water-ways, and leading outwardly through theperiphery of the impeller.

3. 'g1/he combination in a centrifugal pump of an incased impeller, ashaft upon which it is mounted, means forming inclosed chambers atopposite sides of the hub between said hub and casing, said impellerhaving one set of water-ways, of'which open through .one side of the huband thence lead outwardly through the periphery of the impeller, andhaving a second series of water-ways, the inlet ends of which openthrough the other side of the impeller while their outer ends leadthrough the periphery of the impeller, the secondnamed water-ways beingindependent of the first one and serving to create a counterbalance tothe suction on of the impeller.

4.. A centrifugal pump having in combination Ia casing having a centralinlet and the opposite side a peripheral discharge, an impeller inclosedthe inlet ends.

and revoluble within the casing, having af'/ hub adapted to .contactendwise with the opposite sides of the casing, said casin having`annular inwardly extending anges within which the ends of the hub of theimpeller have a running t, said flangesl on the hub and casing andthe'adjacent faces of the hub and casing inclosing side chambers, saidimpeller having curved waterways connecting at their inner ends with theinlet passage 'of the casing, and said impeller Having other andindependent curved water-ways whose inner ends lead through the hub onthe side thereof opposite to that which contains the inlet end of thefirstnamed passages, said second water-ways lealding through theperiphery of the ime ler. p 5. The combination in a centrifugal pump, ofa casing having a centrally located inlet passage upon one side, and anannular peripheraLdischarge passage, 'a Ishaft-driven 20 impellerrevoluble within the casing, said impeller-havin curved waterwaysconnecting with the in et passage at one end of the impeller hub, otherwaterways connecting with the casing through the hub at the op- 25posite side from the inlet passage, flanges FERDINAND w. KEQGH.

Witnesses:

GEO. H. STRONG, CHARLES EDELMAN.

